It is very hard to make experiments for a wheelchair on a waving ship. Also, the test bench, which is used for a real wheelchair, must be very large. So, we need much effort and many costs for it. Therefore, we develop a small test bench for model wheelchairs.

Structure of the Waving Test Bench

The figure of the right shows a structure of the waving test bench. We thought that several electric actuators are used as the power source. However, this bench is adopted a pendulum type for getting a low cost. The table for running tests, which is a veneer board of about 10 mm tickness, is set on a frame of steel. The frame is supported with two bearing units, and has a free rotating motion.

A weight of about 20 kg is hung from the frame, and the weight moves like a pendulum. A cycle of the pendulum is changed by changing of the hight of the weight.

Test Result

As the first trial, we set a fence on the table. It has a circular passage with about 300 mm width. Then, we tried to run a simple model wheelchair on the table. The model wheelchair uses a control system and a drive mechanism of the marketing electric robot for beginers named 'BON-TEN-MARU'. It has an infrared rays sensor system, and the model wheelchair is controled to turn for evasion to the fence.

It was not so difference of locuses both a waving condition (the maximum amplitude is about 10 degs, the cycle is about 2 sec.) and a stationary condition. Because the control system of the BON-TEN-MARU is very well, and the rear tires of the model wheelchair has little slip. However, it was confirmed that the model wheelchair on the waving table had more control times than that of the stationary table. Thus, we expect that the operation of a real wheelchair becomes very hard in the waving condition. We will develop new model wheelchairs, and investigate running characteristics in detail.